crypto: doc - fix header file name

Fixes: 8bc618d6a2e0 ("crypto: doc - Use ahash")
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/Documentation/crypto/api-intro.txt b/Documentation/crypto/api-intro.txt
index beda682..96bd460 100644
--- a/Documentation/crypto/api-intro.txt
+++ b/Documentation/crypto/api-intro.txt
@@ -49,7 +49,7 @@
 
 Here's an example of how to use the API:
 
-	#include <crypto/ahash.h>
+	#include <crypto/hash.h>
 	#include <linux/err.h>
 	#include <linux/scatterlist.h>